A Wideband Noise-Canceling CMOS LNA With Enhanced Linearity by Using Complementary nMOS and pMOS Configurations

A complementary noise-canceling CMOS low-noise amplifier (LNA) with enhanced linearity is proposed. An active shunt feedback input stage offers input matching, while extended input matching bandwidth is acquired by a <inline-formula> <tex-math notation="LaTeX">$\pi$ </tex-math></inline-formula>-type matching network. The intrinsic noise cancellation mechanism maintains acceptable noise figure (NF) with reduced power consumption due to the current reuse principle. Multiple complementary nMOS and pMOS configurations commonly restrain nonlinear components in individual stage of the LNA. Complementary multigated transistor architecture is further employed to nullify the third-order distortion of noise-canceling stage and compensate the second-order nonlinearity of that. High third-order input intercept point (IIP3) is thus obtained, while the second-order input intercept point (IIP2) is guaranteed by differential operation. Implemented in a 0.18-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> CMOS process, the experimental results show that the proposed LNA provides a maximum gain of 17.5 dB and an input 1-dB compression point (IP_{1 dB}) of −3 dBm. An NF of 2.9–3.5 dB and an IIP3 of 10.6–14.3 dBm are obtained from 0.1 to 2 GHz, respectively. The circuit core only draws 9.7 mA from a 2.2 V supply.